Battery tester



G. L. PUGH BATTERY TESTER Dec. 17, 1940.

Filed June 13, 1938 k 2 Sheets-Sheet l g'rvuen vfom G113 ,L. Pugh G. 1 PUGH I BATTERY TESTER Dec. 17, 1940.

2 Sheets-Sheet 2 Filed June 15, 1938 Patented Dec. 17, 1940 uNri-Eo STATES PATENT OFFICE BATTERY res-ran. Guy L. Pugh, Minneapolis, Minn.

Application June 13, 1938, Serial No. 213,481 j I 1 Claims. (01. 175-183) My invention relates to battery testers and has for an object to provide a tester by means of which a storage battery, particularly a battery such as used for automobiles, may be tested and 6 the performance thereof ascertained.

Another object of the invention resides in providing a battery tester in which the performance of two batteries may be compared.

, An object of the invention resides in providing 10 a battery tester in which the battery is subjected to conditions closely simulating those to which the battery is subjected when used in the automobile. J i

A still further object of the invention resides 15 in providing a battery tester in which conditions are provided simulating the conditions a battery in actual use is subjected to when operatedfor an extended period of time for running various electrical appliances such as ordinarily found in automobiles. V

An object of the invention resides in providing a battery tester in which the performance of the battery is indicated through a tachometer or some other speed indicating device calibrated to read directly in revolutions per unit of time of the engine of the automobile when being turned over by the starter.

Another object of the invention resides in utilizing a motor responsive to variations in voltage for operating the tachometer and in connecting said motor across the battery to be tested.

A feature of the invention resides in providing loads for the battery corresponding to the loads to which the battery is subjected'in actual use whereby the drop in voltage of the battery under actual operating conditions will be reproduced to operate the motor and correspondingly give the numberof revolutions per unit of time of the engine. 4 An object of the invention resides in utilizin a loading circuit having a plurality of branches, each having a separate load therein and in selectively connecting one or more of said branches in the circuit to vary the load applied to the battery.

Another object of the invention resides in arranging one of said loads to create a condition similar to that occasioned by a predetermined 50 drop in temperature of the engine at starting.

A still further object of the invention resides in connecting, in series, with the motor, one or more resistances directly reducing the voltage across the motor without appreciably increasing 5 the load upon the battery to create conditions similar to those encountered when the battery has been repeatedly used to operate various electrical appliances such as ordinarily found in automobilea.

An object of the invention resides in the cira cults and apparatus for pplyi g the various loads and resistances and in the manner connecting the loads and resistances in the various circuits and of controlling the operation of said circuits.

Other objects of the invention reside in the in novel combination and arrangement of parts and in the details of construction hereinafter illus trated and/or described.

In the drawings:

Fig. 1 is a perspective view of a battery tester 15 illustrating an embodiment of my invention.

Fig. 2 is a side elevational view of the tachometer and motor for operating the same.

Fig. 3 is a sectional view taken on line 3-3 of Fig. 2.

Fig. 4 is an across-the-line wiring diagram of my invention.

In supplying the trade with automobile storage batteries, the custom has been to furnish numerous types and sizes of batteries for difl'erent services and at different prices. The result is that numerous batteries are ofiered which have different capacities under ordinary conditions and which have still dliferent capacities in cold w climates and which have diflerent lengths of life.

In purchasing batteries, the consumer is confused due to the slight difference in the appearance of the various batteries and at a loss to know which battery to purchase. The present invention provides a battery tester by means of which two batteries may be tested and compared in such a manner that the purchaser may easily visualize the manner of the performance and the characteristics of the respective batteries under consid eration and may determine for himself the suitability of the batteries for the service required.

My invention is best disclosed in the wiring diagram in Fig. 4 which will now be described.

The invention includes a positive bus II .and 45 two negative bm l2 and I3 which are normally disconnected but which may be separately connected to another negative bus 14 by means of which the testing apparatus of the invention is operated. In the drawings I have shown two so batteries l5 and I6 whose performance and operw 2 a masses with clips or other connectors by means of which the same may be readily connectedtothe terminals oi the batteries, The battery II is similarly connectedby means of flexible leads II and t circuit II is utilinedwhich includes a motor 23 responsive to voltage variations and which is connected to a tachometer 20. The motor 28 is connected in this circuitand thesaid circuitextends between the bus II and the bus M. The busii is adapted to be connected to eitherofthe two. buses I! or II by meansot two relays 24: and 28* which are controlled by two master control circuits 28 and 21.

In order to load the battery tdduplicate conditions actually procured in an: automobile s normally open loading circuit]. is employed go which includes a :number of loads which may beconnected to the battery as will be subsequently more fully described. This circuit is adapted to be closedbyqmeans oi either of two relays ll or 32 -whichare operated by the two as master controlcircuits It and 21. These various circuits and the apparatus andlequipment contained therein will now be described in' detail.

The relay llconsists ofa ooilll, anarmature l2 andaicontact II. Relay 3!, similarly so consists ofa coil ll, anarmature ii and a contact ii. The loading circuit 28 includes-a com-' mon conductor II which is connected to the two armatures l2 and "of. the relays II and 32. The contact II of the relay It is connected by as means of a conductor I]: withithe bus l2,;while the contact "101 1115! I2 is similarly connected by means of. conductor I8 withthe bus it. Between the conductor and the bus llgare connected six branch loading circuitsJlpfl, II, It, 40 I1 and II. Inasmuch :as all of the circuits It to 31 inclusive are identical, excepting as to the amount of resistance ineach of, them,,.only the circuit 33 will be described in detail.

The circuit It utilizes a resistance. ll which forms a load for loading either of the batteries II or II. Thisresistance is connected by means of a conductor II to the conductor. 20. The circuit further utilizes a relay' II which is constructed with acoil than armature I and a so contact 4! adapted to be closed when the armature 44 is attracted by the core of the coil 43.

A conductor it connects the resistance with the contact ll, while another conductor 41 connects thearmature 44 with the busil. ,This completes the branch circuit 33. h To simplify the discussion of the invention the? conductors, resistances and relays associated withthe branch circuits 14 to I1. inclusive and with thecontrol circuits thereforwill bereferred to by the same reference numeral as used. in conjunction with the circuit 33 tosether with diiterent suflixes for each of said circuits. It will readily be comprehended that, when the relay 0 is energizedand either of the relays II and ll are energizeda complete circuit is had between the bus II and the particular bus I! or controlled by relays II or 32 and that such circuit includes such of the resistances asjmaybe connected between the bus II and the conductor is. w The circuit II is'similarto the circuitsllito 31 inclusive, exceptingthat a single resistance II is connected in this circuit and no relay is employed for closing said circuit whereby the said resistance is always connected between the bus Ii and the conductor 29 In this circuit the resistance II is connected by means of a conductor II to the conductor 2! and bymeans of conductor I! tothe bus II.

The resistance "is of such .valuethatthe minimum loaddeaired to be placed'upon the bat- 5 tery tested is connected across the battery when this resistaneeialoneis used. Duetothe fact that various automobileshave diflerent amounts of friction and produce different loads. on the batterieswhenvthe engines thereof arebeing 1 started by the startingmotoravarious resistances of diiterent values have to be employedto duplicate theconditions imposed upon the battery whenused with such automobiles. reasonthe various resistancesllmllhitcand lid 15 are. employed and have been so selected that whensaid resistances, inaddition to the resistance ll, :are connectedin the loadins circuit a load of; desired value can beprocured. These resistances'givethe correspondingload atnormal go temperature. i. U s w i In, order to connect the particular desired resistance in the loading circuits selecton switch l4 is utilized. This selector-switch carries a rotating arm II which is constructedwithiour u contactslhll, "and Cl adapted to be cont'acted by said arm. 1 The contacts 0O, 01, Il and I are connected to. four branch control circuits 1|, l2, "and 14. Thefarm ll ofysaid switch is connected to conductor II by means of i a con- '0 'ductor ll. The circuits 11,112. II and" operate thezvarious relays. "a, no and 42c. Each of This resistanceis adapted to be connected in the loading circuit 28 by means of the relay 42d. as previouslyjdescribed. For this W9 i! another branch control circuit 11 is utilized. This circuit includes ml selector switch 'll whichhas m a swinging arm I! and twocontacts II and". The arm II is connected :by means ofa;eon-

' ductor I! with the conductor 2|. Thexcontact Ii is connected with the coillld of relayfld by means of a conductor ll. Another conductor 55 It extends between the coil d and the bus II. The contact llyot; switch ll is the oil-contact and when the switch arm II is on contact", the resistance Ills disconnectedn The resistance lid is preferably oi such value as to produce an additional load such as would result at the lowest temperature at which the battery will herequired to start the automobile. as for example some sub-zero temperature as 20 degrees below.

The master control circuit 28 is a low current as circuit and includes; a push-button II. This push button is connected by means of a conductor I'Lto thebus II and further has connected to it another conductor 0. The master control circuit. It further includes a motor con- 70 trol circuit I! and a loading control circuit II.

The loading control circuit ll has a conductor .82 which is connected to the conductor ll of the master controlcircuit I, and to the coil ll of relay Ii. This circuit also has another. conductor 75 93 which is connected to the coil I of relay 3| and to the bus I2.

The motor control circuit 89 operates the motor relay 24. This relay consists of a coil 94, an armature 95 and a contact 96 adapted to be contacted by the armature 95. Circuit 89 includes a conductor 91 which is connected to the conductor 88 of the master control circuit 26 and to the coil 94 of relay 24. Another conductor 98 connects the other side of this coil to the bus I2. Bus I2 is directly connected to the armature 95 of relay 94 and bus I4 is directly connected to the contact 96 of said relay.

The master control circuit 21 is utilized in connection with the battery I6. This circuit is similar to the circuit 26 and utilizes a push-button 99. A conductor IOI is connected to this pushbutton and to the bus II. Another conductor I02 is also connected to said push-button. The circuit 21 controls two parallel circuits I03 and I04 of which the circuit I03 is the loading control circuit and I04 is the motor control circuit.

Circuit I03 consists of a conductor I 05 which is connected to the coil 54 of relay 32 and to the conductor I 02 of master control-circuit 21. Another conductor I06 is connected to the coil 54 and to the bus I3.

The relay 25 is connected in the motor control circuit I04. This relay has a coil I01, an armature I06 and a contact I09. Circuit I04 includes a conductor III which is connected to the conductor I02 of circuit 21 and to the coil I01 of relay 25. The said coil is further connected by means of a conductor II2 to the bus I3. The contact I09 of relay 25 is connected to the bus I4 while the armature I08, of saidrelay, is connected to the bus I3.

The testing circuit of the invention is indicated by the reference numeral I9 and includes a selector switch I I4 which is provided with a swinging arm H5 and three contacts H6, H1 and H6. The swinging arm I I5 is connected by means of a conductor II9 with the bus I I. The circuit I9 includes three branch circuits, one designated by the reference numeral I2I, being an instrument circuit. The other two circuits are motor circuits for energizing the motor 23 and are designated by the reference numerals I22 and I23. The circuit I22 is a reduced voltage branch and the circuit I23 is a full voltage branch.

The circuit I23 consists of a conductor I24 which is connected to the contact III of switch I I4 and to a conductor I25 leading from the motor 23. Motor 23 is further connected by means of a conductor I26 with the bus I4.

The circuit I22 includes four resistances I3I, I32, I33 and I34 which are connected in series by means of conductors I21. A conductor I28 connects the resistance I3I with the contact II6 of switch II4, while a conductor I29 connects.

the resistance I34 with the conductor I25. Each of the resistances I3I to I34 may be shunted by a jumper switch I35 which by-passes the current ordinarily passing through the same and cuts out the said resistance. It will thus beseen that, when the arm II5, of switch II4 makes contact with contact II6, the current flows from the bus II to the bus I4 and through the various resistances I3I to I34 or any portion of them which may be connected in the circuit which reduce the voltage across the motor 23.

Included in the instrument circuit I2I is a relay I36. This relay comprises a coil I31, an armature I38 and a fixed contact I39. Armature I38 -ible through the opening I63.

is connected by means or a conductor I to the bus II. A conductor I42 is connected to the contact I39 or said relay and to an ammeter I43. Another conductor I44 connects the ammeter I43 with the contact II8 of switch H4. The cality or connection oi. the conductor I to the bus II and the locality of connection of the conductor II9 to the said bus are in actuality widely spaced. The ammeter 31s in reality a 'milivoltmeter which measures the drops in a specified length or the bus II and thus indicates the current flowing through said bus. The coil I 31 of relay I36 is connected by means of a conductor I45 with the bus I4. Another conductor I46 is connected to this coil and to another conductor I41 which in turn is connected to the contact II8 or switch H4. The instrument circuit I2I also includes three voltmeters I5I, I52 and I53. The voltmeter I5I is connected to the conductors I46 and I41 by means of a conductor I48. Another conductor I49 connects the two voltmeters I5I and I52 together and a conductor I54 connects the voltmeters I52 and I53 together. Voltmeter I53 is connected'by means of a conductor I 55 with the bus I4. Two flexible and detachable leads I56 and I51 are connected to the conductor I49 and I54 and may, in turn, be. connected to the connector bars of the battery I6 which connect the terminals of the cells of the battery together.

All of the parts or my invention are contained within a cabinet I58, shown in Fig. 1. This cabinet consists of front and rear walls I59, side walls I6I and a top I62. The top I62 is constructed with openings I63, I64 and I65 which exposeportions of an instrument panel I66 beneath the same. The dial I 61, of the tachometer 20 is visible through the opening I65 and all of the dials of the instruments I43, I 5I I52 and I53 arevis- The selector switches 64, 18 and H4, as well as the switches I35 and push-buttons 85 and 99,.are all accessible through the opening I65. The leads' I1 and I8 connected to buses II and I2 and the leads 2I and 22 connected to buses II and I3 project through the sides I6I of the cabinet I58 and are adapted to be connected to the terminals of the batteries, as shown in Fig. 1.

The batteries I6 and I1 are supported on two racks I68 and I69. Both of these racks being identical, only the rack I69 will be described in detail. This rack consists of two bars HI and I12 which are identical in construction. The bar "I is bent to form a portion I13 which is bolted to the side wall I6I of cabinet I50. This bar is further bent to provide a bracket I14 issuing from the portion I13. Depending from the bracket I14 is a leg I which terminates in a foot I16, extending back toward the wall I 6|. A flange I11,

- on this foot, is bolted to the wall I6I. The battery rests upon the two brackets I14 of the bars "I and I12 where the same is in a position to be easily connected to the apparatus by means of the leads I1 and I6. Attached to the undersides of the foot I16 is a plate I18. This plate has secured. to it casters I19 by means of which the entire cabinet I 58 may be readily moved about.

The motor 23 and tachometer are shown in Figs. 2 and 3. Inasmuch as both motors and tachometers of the kind referred to are well known in the art, the construction thereof has not been shown in detail. The motor 23 has a case IN and an armature shaft I62 projecting therefrom. Tachometer 20 similarly has a case 4 1 I a a mum-11mm proiectingtherefrom. The} with their two shaftsin axial alignment. rorlthis purpose:

twoannular plates is! and. us are employed which'are held in spacedlrelation by meansoi postal" and screws ill passingthrough'sald tached to thembrake shoes Ill. These brake shoesbeanagainst the outer peripheryflof the' III and provide a loadlforthe motor ll. Two tension coil springs lll andillfare hooked to the levers m at the ends; thereof and theendsof thesprinssare attachedto and wound in opposite direction on a shaft 2", rotatably mounted in the Plate i. This shaft is in the nature of a bolt having a head 2.! and is provided adjacent said head with a lock nut; ill by means of which the shaft may be held from rotation. The springs Ill and III are constructed of extremely fine wire which readily bends about the shaft "I. when the shaft!" is rotated in one direction, the tension on the springs lfl Indy". is lessened and when rotated in the opposite direction increased... In

thismanncr the motor "can be loaded thefde amount so thatthessmemay be advjusted to cause the tachometer It Ito properly a t read in revolutions perunitof'time correspond-.

ing to the revolutions the variousjengines which the batteries he .used tqstart... "In the front oi. e cabinet Ill is provided a display window I and ihblckof said window is a-compartment Ill in which commoditiesto The operation of my invention is as follows} "a, lb and "c are selected so thatywhen takenin coniunetionwith the re-' sistance l0, they ailord loads forthe batteryto be tested which would correspond to the produced by the engines and s'tartins motors ,of

the respective automobilesqwith which the bat teries were to beused. The tension of the coil springs lil and "l of the motor:;:tachometer assembly are also so adiustedthat withthe resistances above specified} the tachometer is caused to readvin revolutions per unit corresponding tothe revolutions obtainablewith theparticular makeskof sutomobilesfor which the resistances were selected. Likewise resist- Qancefifld is selected so that the addedloadprodueed by the desired reductlon'intemperature,

is obtained. Similarly the' resistances III to list 3 are selected to produce thereduction ;in voltage: which would be occasioned by the continual use or the various apparatussnd' electrical appliances ordinarily used in an automoblleas for. instance radio, heltel', fan and lights. with theapparatus properly adjusted and with the proper-{resistances installed. the user 1 merely places one battery oneach of the racks I" and Ill aiidconnects theleads i1 and II and Illand 22. thereto. If the purchaser desires to use the.

battery for an automobile o! a' certain class or type the selector switch is adjusted so that i the arm it thereof. makes contact. with the corcompletes theqloading cir nu the coill llaj of nreiay. ssa. conductor in.

"a, conductor lis'andz to:the conductor 1|.

responding contactbf the contacts l8. 01,. or II. Assume fortexample tho said switch was making contact @with :the eontactlI. At first it wouldbedeslredatotesttbe battery for normal use'and arm 'll ofselector switch." wouldbe g "placed on contact-l. This would cutoutlths ref ll battery ilfiis to the same loads.

In each a deflectiomofthe tachometer" isproduced which can belrcadily complred to indicate the reiati'veperforman'ces of the two batteries. When the the following circuits may beitraced. On closing ilrstcompleted. This circuit maybe traced from the bus Ii includes abonductorll, pushbutton ll andconductor 0.1mm conductor is the, currentflows through the. motor control circuit It and the loadinscontrol circuit II; The current from the conductor ll divides thepasses throughconductor ll, thecoil ll of relay II and conductor 08 backtc bus II. The current also so flows through conductorllnthe coil ll of relay 3i and conductor ltjtobusfill. This energizes both oLthe relays tifandllwhich closes contacts formed by the armiturell and contact I! and the armature]! t. II and alsofthe testing l l through the ll. circuits mayibe traced as follows: Commencing withbus ll current ilows throughthe conductor contactfil'l or selectorswitch uythearm "of said switch an'd conductor]. to thecone ductor II. li'rom conductor 2! the current flows throushthe "and contact I! and conductor lite thebus l2. This relaylla and switch formed t the and contact a. Anothercircuit isflnow r shicondu ter mule switch of relay "a, conductor a, resistance Fromthis conductor thelcircuit iscompleted to u the in manner previously described. in corihectionwithcircuit 12. The circuit 84, contalninglresistance "b, is: now closedand said resistance throwd'onthebattery I! as a load. Since; the loadlngflcontrol' circuit Ii 5 and the motor controlcircuit ll in parsliehthe masterkcon'trol circuit relay I4 is energised attheaame time ii is energized "upon the closing of pushbutton II. This completes: thetesting circuit through the motor II as follows} Onelosing otvthe switch of relay 14,; current fiows'from bus ll through conductor" Ill; through the switch arm iil of. switch iil throilshcontactzill, conductor ill as and conductor il lvgto the motor fln l'rom here the currentpasses throushconductor it! to'bus i4 whichwasconnected bymcans ofreiay 24 w bus 12.; 'Ihisenergisesthemotor which drives a the tachometer}! and produces a deflection on 10 push-button u is closed as batteries I6 and II, the push-button 99, controlling the circuits for testing battery I6, is closed and similar circuits established to those previously referred to. As soon as the pushbutton 65 is released, all of the circuits referrred to are open and the device ready to be used to test battery I6. On closing switch 99, the master control circuit 21 is energized and both the motor control circuit I04 and the loading circuit I03 are energized. This closes the loading circuit 28 through the switch formed by the armature 55 and contact 56 of relay 32. At the same time the selector control circuit is operated and the resistance 39 again connected as a load but in this time to the battery I6, current being procured through the bus I3,the switch of relay 25 to motor 23. A comparison of the deflections of the tachometer 20 will indicate the relative performance of the two batteries being compared.

Assume that the purchaser was intent upon buying a battery of insufflcient capacity. On starting at normal temperature the batteries would perhaps show favorably in comparison. The operator, to further show the purchaser the performance, would then manipulate the selector switch 18 and move the arm 19 thereof in contact with contact 8|. This would connect in resistance 39d in a manner similar to resistance 39a and place an additional load upon the battery. The battery of less capacity would then show a lesser reading on the tachometer and in some instances would completely fail to cause the tachometer to move, thus showing that the poorer battery would be unable to start the engine of the automobile at low temperature.

To further compare the batteries, the arm H5 and selector switch I I4 may be shifted to con-' life that he could expect from the better bat-' tery.

If the selector switch H4 is operated to cause the arm II5 to engage contact II8, the instrument circuit I2I would be connected. Upon operation of the push-button 99, bus I4 would be connected to bus I3. The circuit would then be established through conductor II9, switch arm II4, contact II8, conductor I41, conductor I46, the coil I31 of relay I36 and conductor I to bus I4. This would energize the coil I31 of relay I36 and close the switch formed by the armature I39 and contact I39 of said relay. The instrument circuit IZI This circuit would include conductor I4I which is connected to bus II, the switch of relay I36, conductor I42, ammeter I43, conductor I44, selector switch H4 and conductor II9 back to bus II. The ammeter I43 would now be energized. The instrument circuit would also include conductor H9 which is connected to bus II, switch II4, conductor I2I, conductor I48, volt-meter I5I, conductor I 49, volt-meter I52, conductor I54, voltmeter I53 and conductor I55 to bus I4. If the two flexible leads I56 and I51 are connected to would now be complete.

the connectors of the battery I6 the three voltmeters I5I, I52 and I53 will indicate. the respective voltages of the-three cells of the battery. These can thus be compared and in the .good battery all the voltages are the. same. At the same time current flowing through the battery I6 and produced by the loads, previously referred to, would be indicated on the ammeter. By observing the ammeter the rapidity with which the current drops, due to rapiddischarge of the current from thebattery, will become indicated and with a poorer battery the current drops very rapidly showing that, if the engine is not immediatelystarted, the battery would have in'sufllcient capacity to cause the engine to start. It will thus be readily comprehended that two batteries may be readily compared as to performance and the voltage of the various cells and the ability of the batteries to furnish current.

The advantages of my invention are manifest. A highly practical battery tester is provided by means of which the performance of two batteries may be readily compared. By means of my invention the performance may be indicated in such a simple and eifective manner that a person having no particular knowledge of batteries or electrical engineering may readily comprehend the advantages of batteries of different types. The performance of the batteries for use in different types of automobiles may also be demonstrated and the purchaser of the batteries advised as to the proper type and size of battery to use for his particular automobile. My battery tester is attractive in appearance and arranged so as to assist in the sale of batteries. All of the heavy loads are transmitted through relays so that the tester may be manuallyv operated through pushbuttons which the salesman or purchaser may operate without danger.

Changes in the specific form of my invention, as herein disclosed, maybe made within the scope of what is claimed without departing from the spirit of my invention.

Having described my invention, what I claim as new and desire to protect by Letters Patent I claim:

1. A battery tester comprising a loading circuit in which a battery to be tested is connected, 9. testing circuit connected to said battery, a motor in said testing circuit responsive to variations in voltage and subject to the voltage of said battery, said testing circuit having a reduced voltage branch for energizing said motor and a full voltage branch and a selector switch for connecting either of said branches to said motor.

2. A battery tester comprising a loading circuit in which a battery to be tested is connected, a testing circuit, a testing device in said testing circuit and responsive to voltage, said testing circuit being adapted to be connected across said battery, said loading circuit including a plurality of branch circuits each having a load therein, relays-for closing said branch circuits, :3. control circuit having branches for energizing said relays, a selector switch connected in said control circuit and to said branch control circuits, said control circuit being connected in parallel with said loading circuit and being adapted to be energized upon the closing of said loading circuit.

3. A battery tester for batteries for automobiles, saidtester comprising a tachometer calibrated to read in revolutions per unit of time of an automobile engine, a motor responsive to variations in voltage; for operating said tacho- 6 e mm I I meternnd connected acme: aid bettery. end meenltoneiecflvelyloeangnidbetteryinconeccordnnceiwithfliereduotlminwoitegecte ttormity withthe load; lubieotedto betteriee up? the I o! ontheoperetion o! the eta-tin: motorlotvnrimie .PMMMDI 1 4. Abettery teeteriorhetterieetornntomo- .bilel, techometercelibiiee, anteater comprising .1. tnchometer ceii brntedto reedv'in renflutlonoper unit e! flmeo! h'nted to rectum-revolutions per-unit dtimeoi' on automobile endne; nlmotor en nutomobile. engine, e .motor reepomive to 'vuietione inivoitme toromtinz m-vuinflonevm voltage ior operating seid'techw telend eolflbe'tttry epluniity 1o ot brenchloeding'lcircuite connected in pnrenel mlelectlvely londinzinidhetteryin conformity ecrose aidi hettery, reliltnnoeein nid loeding with the loud: eubiectedto bntteriq' upon'jthe circuits, operntion of the stutingmotors o! nrioulnum- 1mm 1s mobiles endiother menus toriiurtherlonding the 1 'ziamwmimum in battery in moordn'ncewith the ndded londge xiztsnidteetetcommlin ntlchometucnlibtetegito in with the of the motors iin of on auto- A i r 5. A buttery teeter iorhettefluHor eutom yoltege ior 'opentinmenW-tnchometer n circuit hntedto rend int-evolutions per :unitot time of motor, a plurality-011M in-leriemin-ld on automobile enzinem motor mnomive to "r1 cimiitmeene for lelectivelylhortini out certnin ntlonl in voltuei'or lfl-ititMflmmeter oi enidredstnnmendmennetor selectively 1ondand cormected across said battery; means for in: said battery in contormityrwith the loedmbzs loading the battery in conformity with the 10nd jected to batteries upon the operation: of testing 25 subjected to the battery upon operation or the motors of various automobiles. -o starting motor of the automobiieend means for v y t t GUY L PUGH. 

